Solved TPU Repeatedly Fails

Patience and perseverance are the only things I can suggest.
When I first started trying to use NinjaFlex it about drove me batty.

Everything works (or not) differently with the more flexible materials. You really do need to think about the model as well as everything else you mentioned... Not all models are even printable with the most flexible materials. They simply can't support their own structure in spots.

In general, the most flexible ones (a la NinjaFlex) are suitable for small or flat-plane style objects and the less flexible (SemiFLex, some nylons) are more suitable for things that need less flex, but still need to be bendable. NinjaFlex is the least generally applicable filament out there... Great if you need to make o-rings and grommets. I like the SemiFlex a LOT better (simply because it is more easy to use and still quite flexible).

 

Just keep your print speeds low. under 20 mm/sec I would say (although you will need to experiment as every machine/environment is different). Mine was happiest at about 10 to 15. As long as your nozzle sizes are correctly in the slicer it should generate the correct speeds for everything.

If you have not done it then calibrating the extruder would be the next thing to do. If it is over or under extruding (even a little bit) that will have a big effect on the flexy stuff.

You can't do thin vertical slabs or uprights with flexible filament since it will sag or collapse as it gets higher and support material is a non-starter.

 

No, extrusion issues are not due to the model. You are likely getting bound up in the GregsWade.
It is frustrating at times and another reason I don't do large models with NinjaFlex. You can have it working great on small prints, but as the printer continues on even a small amount of heat creep will cause the extruder to bind. Even without creep it can happen since the filament is so flexible. Slower speeds are really the only thing you can do with that. If you seriously need flexible filaments a lot then consider upgrading the extruder. There are other options to the GregsWade that are better for flexible filaments. There are even a few threads on here about those. For me the need was not routine and creeping along slow was good enough (along with the feeder tube modification) since I had nothing large to print.

 

Yes, heat creep is where the heat from the hotend creeps up the body of the hotend to the point where the filament softens in the cold-section. Normal hotends are large enough for this to normally not be an issue, but the compact style of the Hexagon, E3D and similar means that there is not enough metal so a cooling fan MUST be running.

The 40mm Noctua should be moving enough air. I am still using the ones E3D included with their hotends and have had no issues.

 

My e3d 30mm fan pushes way more air than my 40mm and i switch back to the 30 for ninja or semiflex. I think its the duct i use on the 40 that blocks my air

 

Oh and when i run .8 nozzle i 50% my overall speed. Try 5mm/s i know it sounds aweful but it just might work.

 

The standard one that comes with the e3d hotend.

Are you running the stock hotend ?(hexagon)

 

Ill try to find the brand name on my fan as soon as i finish this print im running. Noctura is a great fan. I have had good luck with evercool from amazon.

I will tell you before you buy anything i personally could not run flexible worth a darn with the hexagon. I never figured out why. I do believe some members have had good luck doing so but i just had fail after fail.

 

It is for the Hexagon. Those get stuck at around 1.8-ish Might work a little better on E3D, but still that is out of tolerance in my book.

 

Yep out of tolerance. Id contact the seller and ask for a replacement.

 

If they let you keep it let me.know ;-) i run an e3d and it accepts some out of spec filament with the 2.0 bore vs the hexagon 1.8 bore

 

I agree, with your symptoms this does pretty much explain it.